Agroecology - Gliessman

382  Download (0)

Full text


The Conversion to

Sustainable Agriculture

Principles, Processes, and Practices


Series Editor: Clive A. Edwards

Agroecosystems in a Changing Climate

Paul C.D. Newton, R. Andrew Carran, Grant R. Edwards, and Pascal A. Niklaus Agroecosystem Sustainability: Developing Practical Strategies

Stephen R. Gliessman

Agroforestry in Sustainable Agricultural Systems

Louise E. Buck, James P. Lassoie, and Erick C.M. Fernandes Biodiversity in Agroecosystems

Wanda Williams Collins and Calvin O. Qualset

The Conversion to Sustainable Agriculture: Principles, Processes, and Practices Stephen R. Gliessman and Martha Rosemeyer

Interactions between Agroecosystems and Rural Communities Cornelia Flora

Landscape Ecology in Agroecosystems Management Lech Ryszkowski

Multi-Scale Integrated Analysis of Agroecosystems Mario Giampietro

Soil Ecology in Sustainable Agricultural Systems Lijbert Brussaard and Ronald Ferrera-Cerrato Soil Organic Matter in Sustainable Agriculture

Fred Magdoff and Ray R. Weil Soil Tillage in Agroecosystems

Adel El Titi

Structure and Function in Agroecosystem Design and Management Masae Shiyomi and Hiroshi Koizumi

Sustainable Agroecosystem Management: Integrating Ecology, Economics and Society Patrick J. Bohlen and Gar House

Tropical Agroecosystems John H. Vandermeer

Advisory Board

Editor-in-Chief Clive A. Edwards

The Ohio State University, Columbus, Ohio

Editorial Board

Miguel Altieri, University of California, Berkeley, California

Lijbert Brussaard, Agricultural University, Wageningen, The Netherlands David Coleman, University of Georgia, Athens, Georgia

D.A. Crossley, Jr., University of Georgia, Athens, Georgia Adel El-Titi, Stuttgart, Germany

Charles A. Francis, University of Nebraska, Lincoln, Nebraska Stephen R. Gliessman, University of California, Santa Cruz, California Thurman Grove, North Carolina State University, Raleigh, North Carolina Maurizio Paoletti, University of Padova, Padova, Italy

David Pimentel, Cornell University, Ithaca, New York Masae Shiyomi, Ibaraki University, Mito, Japan Sir Colin R.W. Spedding, Berkshire, England


CRC Press is an imprint of the

Taylor & Francis Group, an informa business Boca Raton London New York

The Conversion to

Sustainable Agriculture

Principles, Processes, and Practices

Edited by

Stephen R. Gliessman

Martha Rosemeyer


6000 Broken Sound Parkway NW, Suite 300 Boca Raton, FL 33487-2742

© 2010 by Taylor and Francis Group, LLC

CRC Press is an imprint of Taylor & Francis Group, an Informa business No claim to original U.S. Government works

Printed in the United States of America on acid-free paper 10 9 8 7 6 5 4 3 2 1

International Standard Book Number: 978-0-8493-1917-4 (Hardback)

This book contains information obtained from authentic and highly regarded sources. Reasonable efforts have been made to publish reliable data and information, but the author and publisher cannot assume responsibility for the validity of all materials or the consequences of their use. The authors and publishers have attempted to trace the copyright holders of all material reproduced in this publication and apologize to copyright holders if permission to publish in this form has not been obtained. If any copyright material has not been acknowledged please write and let us know so we may rectify in any future reprint.

Except as permitted under U.S. Copyright Law, no part of this book may be reprinted, reproduced, transmit-ted, or utilized in any form by any electronic, mechanical, or other means, now known or hereafter inventransmit-ted, including photocopying, microfilming, and recording, or in any information storage or retrieval system, without written permission from the publishers.

For permission to photocopy or use material electronically from this work, please access www.copyright. com ( or contact the Copyright Clearance Center, Inc. (CCC), 222 Rosewood Drive, Danvers, MA 01923, 978-750-8400. CCC is a not-for-profit organization that provides licenses and registration for a variety of users. For organizations that have been granted a photocopy license by the CCC, a separate system of payment has been arranged.

Trademark Notice: Product or corporate names may be trademarks or registered trademarks, and are used

only for identification and explanation without intent to infringe.

Library of Congress Cataloging‑in‑Publication Data

The conversion to sustainable agriculture : principles, processes, and practices / editors: Stephen R. Gliessman, Martha Rosemeyer.

p. cm. -- (Advances in agroecology) Includes bibliographical references and index. ISBN 978-0-8493-1917-4 (hardcover : alk. paper)

1. Sustainable agriculture. 2. Sustainable agriculture--Case studies. I. Gliessman, Stephen R. II. Rosemeyer, Martha. III. Title. IV. Series: Advances in agroecology. S494.5.S86C665 2010

630--dc22 2009040253

Visit the Taylor & Francis Web site at and the CRC Press Web site at




Preface...vii Contributors ...ix


SectIon Basic Principles


Chapter The Framework for Conversion ...3

Stephen R. Gliessman


Chapter What Do We Know about the Conversion Process?

Yields, Economics, Ecological Processes, and Social Issues ... 15

Martha E. Rosemeyer


Chapter The History of Organic Agriculture... 49

Rachael J. Jamison and John H. Perkins


SectIon I Global Perspectives


Chapter Northern Midwest (U.S.): Farmers’ Views of the Conversion

Process ... 67

Paul Porter, Lori Scott, and Steve Simmons


Chapter Pacific Northwest (U.S.): Diverse Movements toward

Sustainability Amid a Variety of Challenges ... 91

Carol Miles, David Granatstein, David Huggins, Steve Jones, and James Myers


Chapter California (U.S.): The Conversion of Strawberry Production ... 117

Stephen R. Gliessman and Joji Muramoto


Chapter Ontario, Canada: Lessons in Sustainability from Organic

Farmers ... 133



Chapter Mexico: Perspectives on Organic Production ... 165

María del Rocío Romero Lima


Chapter Mexico: Traditional Agriculture as a Foundation for

Sustainability ... 179

Alba González Jácome


Chapter 0 Cuba: A National-Level Experiment in Conversion ...205

Fernando R. Funes-Monzote


Chapter 1 The European Union: Key Roles for Institutional Support and Economic Factors ... 239

Gloria I. Guzmán and Antonio M. Alonso


Chapter 2 Japan: Finding Opportunities in the Current Crisis ... 273

Joji Muramoto, Kazumasa Hidaka, and Takuya Mineta


Chapter 3 The Middle East: Adapting Food Production to Local

Biophysical Realities ...303

Alireza Koocheki


Chapter 4 Australia: Farmers Responding to the Need for Conversion ... 317

David Dumaresq and Saan Ecker


SectIon I the Way Forward


Chapter 5 Transforming the Global Food System ... 345

Stephen R. Gliessman




This book project began many years ago when the second editor, while still a graduate student, was asked by the first editor to carry out a literature search on the conversion process from conventional to alternative agroecosystems. During the course of this research, funded at that time by the Noyce Foundation, Martha Rosemeyer encountered Stuart Hill’s three-level classification system for conver-sion. Using agroecology as a methodological tool for both researching and pro-moting the conversion process, and with growing awareness that any change in agriculture also implies social transformations, we eventually added a fourth level to Hill’s taxonomy. We described the four levels of conversion in Agroecology:

The Ecology of Sustainable Food Systems (CRC Press, 1997), but it remained to explore more deeply what conversion meant and to learn how it was actually proceeding around the world. With continuing support from the Ruth and Alfred Heller Chair in Agroecology at University of California–Santa Cruz (UCSC), we conceived of this project and pushed the book forward.

Eric Engles carried out his editing magic on all parts of the book, and ultimately was the person who really extracted the work from all of us. Master indexing was done by Michael Brackney. John Sulzycki, at CRC/Taylor & Francis, with all of his commitment to agroecology, created the space for this project in the first place. And finally, we sincerely appreciate and acknowledge the hard work of all the chapter authors in promoting the conversion process around the world, and thank them for their patience in bringing the book to completion.




Antonio M. Alonso

Centro de Investigación y Formación de Agricultura Ecológica y Desarrollo Rural

Santa Fe (Granada), Spain E. Ann Clark

Plant Agriculture University of Guelph Guelph, Ontario, Canada David Dumaresq

The Fenner School of Environment and Society

The Australian National University Canberra, ACT, Australia

Saan Ecker

The Fenner School of Environment and Society

The Australian National University Canberra, ACT, Australia

Fernando R. Funes-Monzote Estación Experimental “Indio Hatuey” Universidad de Matanzas

Central España Republicana, Perico, Matanzas, Cuba

Stephen R. Gliessman

Department of Environmental Studies University of California, Santa Cruz Santa Cruz, California

Alba González Jácome Universidad Iberoamericana AC Santa Fe, Mexico City, Mexico

David Granatstein

Center for Sustaining Agriculture and Natural Resources

Washington State University Wenatchee, Washington Gloria I. Guzmán

Centro de Investigación y Formación de Agricultura Ecológica y Desarrollo Rural

Santa Fe (Granada), Spain Kazumasa Hidaka

Agroecology Rural Community Management

College of Agriculture Ehime University

Tarumi, Matsuyama, Japan David Huggins

U.S. Department of Agriculture– Agricultural Research Service (USDA-ARS)

Washington State University Pullman, Washington Rachael J. Jamison

Washington State Department of Ecology

Lacey, Washington Steve Jones

Mount Vernon Northwestern Research and Extension Center

Washington State University Mount Vernon, Washington


Alireza Koocheki Faculty of Agriculture

Ferdowsi University of Mashhad Mashad, Iran

Carol Miles

Washington State University Mount Vernon Northwestern

Washington Research and Extension Center

Mount Vernon, Washington Takuya Mineta

Laboratory of Environmental Evaluation

Department of Rural Environment National Institute for Rural Engineering


Kannondai, Tsukuba, Japan Joji Muramoto

Program in Community and Agroecology (PICA)

University of California, Santa Cruz Santa Cruz, California

James Myers

Oregon State University Department of Horticulture Corvallis, Oregon

John H. Perkins

The Evergreen State College Olympia, Washington Paul Porter

Agronomy/Plant Genetics University of Minnesota St. Paul, Minnesota

María del Rocío Romero Lima Programa de Agricultura Orgánica Universidad Autonoma Chapingo Chapingo, México

Martha E. Rosemeyer The Evergreen State College Olympia, Washington Lori Scott University of Minnesota St. Paul, Minnesota Steve Simmons University of Minnesota St. Paul, Minnesota Jennifer Sumner

Adult Education and Community Development Program OISE/University of Toronto Toronto, Ontario, Canada







The Framework

for Conversion

Stephen R. Gliessman

1.1 The Need for CoNversioN

As we near the end of the first decade of the twenty-first century, we are confronted with an increasing number of signs that our global food system is rapidly approach-ing, if not already in, a condition of crisis. Issues and problems that go beyond the litany of environmental degradation, pest and disease resistance, loss of genetic diversity, increasing dependence on fossil fuels, and others (Gliessman, 2007) now confront us, creating what is increasingly being called the food crisis. We now face a dramatic rise in food prices, increases in hunger and malnutrition, and even food riots in places in the world where people no longer have access to sufficient food. Making things worse, too many small traditional and family farmers have been forced off their land and out of agriculture due to a wide variety of reasons, includ-ing the neoliberalization of trade policy, the loss of support for local food produc-tion systems, the entrance of speculative financial capital into food markets, changes in diets and food preferences that accompany greater access to global markets, the agrofuel boom and resulting diversion of food energy to feed the global demand for energy, and the enormous spike in the cost of petroleum in 2008 that caused a rise in the cost for all fossil-fuel-based inputs to agriculture (Rosset, 2006, 2008).

On a global scale, agriculture was very successful in meeting a growing demand for food during the latter half of the twentieth century. Yields per hectare of basic crops such as corn, wheat, and rice increased dramatically, food prices declined, the rate of increase in food production was generally able to keep up with the rate of population growth, and chronic hunger diminished. This boost in food produc-tion was due mainly to scientific advances and technological innovaproduc-tions, including the development of new plant varieties, the use of fertilizers and pesticides, and the growth of extensive infrastructures for irrigation. But the elements of the food crisis noted above are signs that this era of ever-rising food production may be coming to


1.1 The Need for Conversion ...3

1.2 Guiding Principles for Conversion ...4

1.3 Steps in the Conversion Process ...6

1.4 The Chapters in This Book ...9


an end. We may be approaching a limit in the amount of food that we can produce relatively inexpensively, given the limited amount of arable land left on the earth and the degraded condition of much that is already being cropped.

At the same time, we face a problem that in the long-term will be even more chal-lenging to the global food system: the techniques, innovations, practices, and policies that have allowed increases in productivity have also undermined the basis for that productivity. They have overdrawn and degraded the natural resources upon which agriculture depends—soil, water resources, and natural genetic diversity. They have also created a dependence on nonrenewable fossil fuels and helped to forge a sys-tem that increasingly takes the responsibility for growing food out of the hands of farmers and farmworkers, who are in the best position to be stewards of agricultural land. In short, our system of agricultural production is unsustainable—it cannot con-tinue to produce enough food for the growing global population over the long-term because it deteriorates the conditions that make agriculture possible.

Our global food system also faces threats not entirely of its own making, most nota-bly the emergence of new agricultural diseases (such as mad cow and antibiotic-resistant salmonella), climate change, a growing demand for energy, and an approaching decline in the production of the fossil fuel energy that has subsidized agricultural growth.

Considering all these factors, it is clear that none of the strategies we have relied on in the past—creating higher-yielding varieties, increasing the area of irrigated land, applying more inorganic fertilizers, reducing pest damage with pesticides—can be counted on to come to the rescue. Indeed, it is becoming increasingly evident that these strategies, combined with the commoditization of food and the control of global food production by large transnational agribusiness interests, are a part of the problem, not its solution. The only way to avoid a deepening of the food crisis is to begin converting our unsustainable systems of food production into more sustainable ones. It is the goal of this book to establish a framework for how this conversion can be accomplished, and to provide examples from around the world where the conversion is under way.

1.2 GuidiNG PriNCiPles for CoNversioN

Farmers and ranchers have a reputation for being innovators and experimenters, con-stantly testing new seed, plants, breeds, inputs, and practices. They adopt new farm-ing practices and marketfarm-ing arrangements when they perceive that some benefit will be gained. The heavy emphasis on high yields and farm profits over the past 40 to 50 years has achieved remarkable results, but with an accompanying array of nega-tive impacts that have restricted farmer-initiated innovation. After responding to this overriding economic focus in agriculture, many farmers are now choosing to make the transition to practices that not only are more environmentally sound in the short-term, but also have the potential for contributing to sustainability for agriculture in the long term (Gliessman, 2001). Several factors are driving the changes in our food systems that are facilitating this transition process. These include factors that range from on-farm issues to conditions well beyond farming communities:

The uncertain cost of energy. •

The low profit margins of conventional practices. •


The development of new practices that are seen as viable options, especially •

in organic agriculture.

Increasing environmental awareness among consumers, producers, and •


A better understanding of the close link between diet and the recent increases •

in health issues, such as obesity, diabetes, heart disease, and cancer. A growing appreciation for the need to integrate conservation and liveli-•

hoods in farming communities.

New and stronger markets for organically and ecologically grown and pro-•

cessed farm products.

There are many factors that need to be dealt with in the process of converting to sustainable food systems. Many of these factors directly confront the farmer on the farm. As described in many of the chapters of this book, despite the fact that farmers often suffer both yield reduction and loss of profits in the first year or two after ini-tiating conversion, most of those who persist eventually realize both economic and ecological benefits from having made the conversion. Obviously, a farmer’s chances of making it through the transition process successfully depend in part on his or her ability to adjust the economics of the farm operation to the new relationships that come from farming with a different set of input and management costs. But as some chapters demonstrate, success in the conversion process is also dependent on fac-tors beyond the farmer’s control. These include the development of different market-ing systems, pricmarket-ing structures, policy incentives, and other changes that reach all aspects of the food system, from the grower on one end to the eater on the other.

While the economic goal of conversion is to maintain profitability, the ecologi-cal goal is to initiate a complex set of very profound changes. As the types of inputs change, and practices shift to ecologically based management, agroecosystem struc-ture and function change as well. As some authors show in this volume, a range of ecological processes and relationships are altered, beginning with aspects of basic soil structure, organic matter content, and diversity and activity of soil biota. Eventually major changes also occur in the activity and relationships of weed, insect, and disease populations, especially the balance between beneficial and pest organ-isms. Ultimately, nutrient dynamics and cycling, energy use efficiency, and overall system productivity are impacted. Measuring and monitoring these changes during the conversion period can provide the foundations for developing practical guide-lines and indicators of sustainability that will promote the changes that need to occur in the agriculture of the future.

The following principles serve as general guidelines for navigating the overall trans-formation that food systems undergo during the conversion process (Gliessman, 2007):

Shift from extractive nutrient management to recycling of nutrients, with •

increased dependence on natural processes such as biological nitrogen fixa-tion and mycorrhizal relafixa-tionships.

Use renewable sources of energy instead of nonrenewable sources. •

Eliminate the use of nonrenewable off-farm inputs that have the potential to •


When materials must be added to the system, use naturally occurring and •

local materials instead of synthetic, manufactured inputs.

Manage pests, diseases, and weeds as part of the whole system instead of •

“controlling” them as individual organisms.

Reestablish the biological relationships that can occur naturally on farms •

and ranches instead of reducing and simplifying them.

Make more appropriate matches between cropping patterns and the produc-•

tive potential and physical limitations of the agricultural landscape. Use a strategy of adapting the biological and genetic potential of agricultural •

plant and animal species to the ecological conditions of the farm rather than modifying the farm to meet the needs of the crops and animals.

Value most highly the overall health of the agroecosystem rather than the •

outcome of a particular crop system or season.

Emphasize the integrated conservation of soil, water, energy, and biologi-•

cal resources.

Build food system change on local knowledge and experience. •

Carry out changes that promote justice and equity in all segments of the •

food system.

Incorporate the idea of long-term sustainability into overall agroecosystem •

design and management.

To varying degrees, these principles are reflected in the conversion efforts described in the chapters of this book. The integration of these principles creates a synergism of interactions and relationships from the farm to the table that eventually leads to the development of the properties of sustainable food systems.

1.3 sTePs iN The CoNversioN ProCess

For many farmers and ranchers, rapid conversion to sustainable agroecosystem design and practice is neither possible nor practical. As a result, many conversion efforts proceed in slower steps toward the ultimate goal of sustainability, or are sim-ply focused on developing food production systems that are somewhat more envi-ronmentally sound or slightly more economically viable or just. For the observed range of conversion efforts seen in this book, four distinct levels of conversion can be discerned. These levels—originally proposed by Hill as three steps (1985, 1998), and expanded to four levels in Gliessman (2007)—help us describe the steps that are actually taken in converting from modern conventional or industrial agroecosystems. They can serve as a map outlining a stepwise, evolutionary conversion process. They are also helpful for categorizing agricultural research as it relates to conversion.

Level 1: Increase the efficiency and effectiveness of conventional practices

in order to reduce the use and consumption of costly, scarce, or environ-mentally damaging inputs. The goal of this approach is to use inputs more efficiently so that fewer inputs will be needed and the negative impacts of their use will be reduced as well. This approach has been the primary emphasis of much of the agricultural research of the past four to five decades,


through which numerous agricultural technologies and practices have been developed. Examples include optimal crop spacing and density, genomics, improved machinery, pest monitoring for improved pesticide application, improved timing of operations, and precision farming for optimal fertilizer and water placement. Although these kinds of efforts may reduce the nega-tive impacts of conventional agriculture, they do not help break its depen-dence on external human inputs. While this may be a reason for arguing that they do not represent conversion at all, it must be recognized that in the real world of agriculture, level 1 efforts often represent a crucial foundation for initiating efforts at the other levels.

Level 2: Substitute conventional inputs and practices with alternative


tices. The goal at this level of conversion is to replace resource-intensive and environment-degrading products and practices with those that are more environmentally benign. The recent expansion in organic farming and eco-logical agriculture research has emphasized such an approach. Examples of alternative practices include the use of nitrogen-fixing cover crops and rota-tions to replace synthetic nitrogen fertilizers, the use of biological control agents rather than pesticides, and the shift to reduced or minimal tillage. At this level, the basic agroecosystem structure is not greatly altered; hence, many of the same problems that occur in conventional systems also occur in those with input substitution.

Level 3:

Redesign the agroecosystem so that it functions on the basis of a new

set of ecological processes and relationships. At this level, overall system design eliminates or at least mitigates the root causes of many of the problems that still exist at levels 1 and 2. In other words, rather than finding sounder ways of solving problems, the problems are prevented from arising in the first place. Whole-system conversion studies allow for an understanding of yield-limiting factors in the context of agroecosystem structure and function. Problems are recognized, and thereby prevented, by internal site- and time-specific design and management approaches, instead of by the application of external inputs. An example is the diversification of farm structure and man-agement through the use of rotations, multiple cropping, and agroforestry.

Level 4: Reestablish a more direct connection between those who grow

the food and those who consume it, with a goal of reestablishing a culture of sustainability that takes into account the interactions between all com-ponents of the food system. Conversion occurs within a social, cultural, and economic context, and that context must support conversion to more sustainable systems. At a local level, this means consumers value locally grown food and with their food purchasing, support the farmers who are striving to move through conversion level 1 to levels 2 and 3. In a sense, this means the development of a kind of “food citizenship,” where every-one forms part of the system and both is able to influence change and be influenced by it. The more we move to this level of integration and action for change in food systems in communities around the world, the closer we move toward building a new culture and economy of sustainability (Hill, 1998; Gliessman, 2007).


In terms of research, agronomists and other agricultural researchers have done a good job of transitioning from level 1 to level 2. Research on the transition to level 3 has been very limited until recently, and work on level 4 is only just getting started. The chapters in this book describe work that is ongoing at several of these levels. The transition from level 1 to level 2 appears most commonly in the chapters of this book as the goal of reaching standards such as organic certification. As shown in Figure 1.1, we have seen considerable growth in the organic food industry in just the past decade, and this indicates that many farmers have reached level 2. The data pre-sented here are from the sale of organic food in the United States, but are indicative of what is happening in other parts of the world as well.

But we must be sure that the movement toward sustainability does not stop at level 2. While the so-called mainstreaming of organic food availability signals a welcome shift in consumer consciousness, it also indicates that the most powerful elements of the conventional, industrialized food system are working to co-opt and contain change. We need to think beyond organic to all levels of the food system, with the idea of transcending product-focused thinking and maintaining a focus on achieving fully sustainable food systems.

In those chapters where agroecology provides the basis for researching level 3, we can see where the redesign and restructuring process is well under way. It is in those few examples in which all members of the food system value the principles of sustainability and relationship where we will we begin to find answers to larger, more abstract questions about the conversion process, such as what sustainability is

$0 $1,000 $2,000 $3,000 $4,000 $5,000 $6,000 $7,000 $8,000 $9,000 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008

fiGure 1.1 Sales of organic fruits and vegetables in the United States during the past decade. Sales are in the millions of U.S. dollars. (Nutrition Business Journal []; Santa Cruz Sentinel, March 18, 2009, pp. A1–A2.)


and how we will know we have achieved it. Ultimately, thinking about sustainability at level 4 can begin to guide the conversion process at all levels, promoting a more rapid transition to full food system sustainability for all parts, peoples, and scales of the global food system.

1.4 The ChaPTers iN This Book

The chapters that follow are highly diverse, each with a unique perspective shaped by the author’s location, research, and central concerns. Some authors concentrate on explaining the challenges, while others look more closely at signs of progress and opportunities for change. Some choose a comprehensive overview approach, while others make use of more narrowly focused case studies and examples.

The second chapter provides a review of how researchers have attempted to apply the conversion framework, design experiments, and studies to evaluate conversion; carry out ecological, economic, and social analysis of results; and develop indicators that can tell us if particular conversion efforts are moving us toward sustainability. It is clear that we know how to study the pieces of agroecosystems separately, but we are still limited in our ability to work with the complexities of entire systems simultaneously. This is one of the reasons it is very easy to get stuck at level 2 in the conversion process.

The history of the conversion process as we have known it so far is essentially the history of the organic agriculture movement. This is the topic of Chapter 3. In this chapter, Jamison and Perkins trace the roots of the movement back to the early twentieth century and chronicle its development in the United States. They describe how, in its current phase of burgeoning popularity, the organic movement is in dan-ger of getting stuck at level 2. Organic agriculture is increasingly being captured by market forces as production is concentrated in the hands of larger and vertically integrated growing, processing, shipping, and marketing operations. Knowing the history of the organic movement and the challenges it faces today provides the necessary context for understanding the conversion process as it is described in the chapters that follow.

Despite the fact that organic certification and expanding organic markets have motivated many farmers to convert to alternative production practices, it has also not been the only reason. As described by Porter, Scott, and Simmons in Chapter 4, there are many different constraints facing farmers in such places as the north-west Midnorth-west of the United States. Farming in a difficult ecological transition zone with harsh winters and short growing seasons limits cropping options, and a combination of economic and social limitations limits choice and market access. But despite these limitations, farmers have been making the transition to more sustainable practices. The farmers themselves refer to an evolutionary or even “transformational” process they go through as they make the decision to change their farming systems, sharing in a set of revealing interviews how so much of the conversion process is determined by personal values, family needs, and even the degree of community support. Economics play an important role, but just decid-ing to farm differently, believdecid-ing in the choice, and godecid-ing through the learndecid-ing process to make it happen shows how level 4 thinking is integral to driving the


change process. As one farmer said, the conversion process is “not nearly com-plete, and we expect that it never will be. It’s a biological system, alive and in need of observation, tending and rebalancing daily…. It takes time and a fair amount of courage and faith.”

Every farming region faces different challenges to the sustainability of its food systems. Each region also takes different steps along the conversion pathway in con-fronting these challenges. As Miles et al. discuss in Chapter 5, the Pacific Northwest presents a spectrum of different challenges as one moves from the moister coastal areas through the interior valleys to the extensive dryland areas farther inland. The most obvious challenges are a combination of climatic, soil, and pest management issues. The most common approach to overcoming such challenges is to engage in level 1 conversion. Conventional farmers and researchers team up to develop new inputs and practices that increase efficiency, reduce environmental impacts, and improve economic return. But when we examine each region in particular, the value of different conversion approaches becomes apparent. The interior wheat-based dry-land systems have tried to confront the overriding sustainability issue of soil erosion and degradation. At level 1, this has meant moving to conservation tillage to try to reduce soil exposure and loss to wind and water erosion. The description by Miles et al. of their ongoing research project that integrates direct seeding into crop residues with precision agriculture techniques, using multiple georeference points per acre that improve input use and yields, shows the strides that level 1 research can make. But the systems are still extremely intensive, and as the authors of this chapter state, the current systems are not sustainable. The conversion to level 2 and organic pro-duction still represents a very small proportion of the area farmed, and the farmers who have made this conversion face multiple challenges, including limited market access, a need for very intensive soil cultivation, and lack of appropriate seed and farming practices. Despite the fact that both these level 1 and 2 conversions generate beneficial ecosystem services, they are not rewarded at the marketplace. Some level 4 thinking is needed for this to happen.

In the intermediate orchard regions, Miles and coauthors show how conventional systems have been extremely innovative in developing new management technolo-gies at level 1, and organic systems have developed very sophisticated management approaches at level 2, but neither one has advanced to the next two levels. Production remains intensive and single crop based, and market chains are long and distant from consumers. The authors’ call for more direct market structures is a call for level 4 conversion, something that has become essential in the conversion process in the maritime horticultural zone. Under pressures from advancing urbanization, loss of agricultural land, and urban dwellers’ concerns about noise, dust, smells, and pesticides, farmers in this region have moved ahead of their two interior coun-terparts with both level 3 and level 4 conversion steps. By moving to level 3 with crop rotations, diversification, and other redesign approaches, and to level 4 through direct marketing, farmers’ markets, and community-supported agriculture (CSA), many farmers who were already at level 2 with organic certification are now moving beyond that toward sustainability.

In Chapter 6, Gliessman and Muramoto show how difficult it is for conventional strawberry growers on the central coast of California to take risks that threaten the


economic viability of a crop that can cost in excess of $25,000 per acre to plant and maintain. Although some farmers in this area had begun to transition to level 2 organic production, it was not until a key input (methyl bromide) was banned that the pressure for conversion really took hold. The first step in the conversion process was the establishment of organic certification. But since there was so little knowl-edge about how to grow strawberries organically, the side-by-side comparison of conventional and organic plots during the transition process was a necessary first step. Once certification was achieved, however, continued monitoring and work with farmers was necessary in order to identify the limits to sustainability of the organic system. Once these limits could be identified, it became obvious that level 3 redesign needed to occur, and this type of work is ongoing, with many steps yet to be taken. Meanwhile, the push for alternative design and management strategies is being pro-moted by the level 4 connections that continue to develop between growers and con-sumers, with direct marketing, new relationships, and emerging understanding of food systems sustainability promoting deeper change.

The complexity of reaching levels 3 and 4 in the conversion process is highlighted by Clark and Sumner in Chapter 7. Their discussion of the contested nature of the term sustainability provides a useful way of thinking about how level 4 thinking can be generated and promoted. They refer to the work of McMurtry (2003) and his idea of “life capital” being “life-wealth that produces more wealth not just by sustain-ing it, but by ‘value-addsustain-ing’ to it through providsustain-ing more and better life goods.” In other words, the values and beliefs inherent in the social, cultural, and environmen-tal aspects of sustainability must be integrated with the economic aspects that so strongly guide most of conventional agriculture. The focus on enhancing the mul-tiple and complex relationships that can occur in food systems becomes the focus of level 4 conversion. The lessons learned from farmers who have converted to organic production (mostly at level 2) give us ways of considering if organic is helping move food systems toward sustainability or diverting them from this goal. It is interesting to note that most farmers in Ontario would fall into what would be considered the small farmer category, and that off-farm income for these farmers was at least twice as much as on-farm income in the last census. As discussed above, combining these two modes of livelihood may be an important strategy for the economic side of farm system sustainability.

Clark and Sumner provide candid evidence from their analysis of Canadian organic agriculture that many farmers who convert do so for level 4 reasons—for “heartfelt concerns about personal and environmental health,” coupled with an emerging alternative market structure with farmers’ markets and CSA. The farm-ers who enter into convfarm-ersion to organic are clear in their recognition of a range of ecological, agronomic, social, and economic constraints on the sustainability of the alternative systems. Since so many of the farmers who choose to farm differently mostly choose to “go it alone,” a new set of economic and policy options are needed. Clark and Sumner show that no one event or issue pushes farmers in the direction of organic production, creating a “matrix of encouragement” that needs to be under-stood in order to move the conversion process forward more effectively. This can be aided greatly by further development of a range of ecological, social, and economic indicators. Clark and Sumner are especially effective in pointing out some of the


social and ecological indicators that will help promote the conversion to level 4 in food systems, yet are realistic in the difficult challenges we face in ensuring that some of the same economic factors that are limiting options for alternative growers do not continue to threaten future food system sustainability.

In her review of the history of organic agriculture in Mexico (Chapter 8), Romero points out how the emergence of organic production systems has not been merely a matter of introducing technological change in agriculture, but is also a result of questioning the role of agriculture in society in general and of the kind of develop-ment model needed by the farming sector. She introduces argudevelop-ments for level 4 thinking by raising the issue of food security and arguing for more equitable rela-tionships between the rural and urban sectors, between agriculture and industry, and between energy and food policy. She calls for more participation of the peasant sector in the development of agricultural and food policy. She is clear in her claim that the elements of a new paradigm for food systems can be found in the peasant and indigenous communities that have spearheaded the conversion to organic agri-culture in Mexico.

Interestingly, though, Romero also points out how—despite the fact that much of the conversion to organic is only taking place at level 2, with input substitution and policy support for the development of international export markets—there is the emergence of a “different kind of organic agriculture.” This is one grounded in rural communities, and aims to build healthy soil, plants, animals, and human beings.

González Jácome goes even further back in history and describes the deep roots of traditional agriculture in Mexico, adding an even stronger cultural foundation to the argument that local knowledge, customs, and food system practices are crucial for sustainability. She is clear, however, about the seriousness of the threats to tra-ditional agriculture, and how tratra-ditional farmers, despite having spearheaded much of the organic movement in Mexico, are also being threatened by globalization, lack of access to markets for their products, loss of local biodiversity, outmigration from rural communities, and a breakdown of the vital knowledge development and trans-fer processes so important for small-scale, rural cultures. There are many ways that traditional knowledge systems can help the conversion process, and most of them operate at levels 3 and 4. The human-directed selection and adaptation process that has gone on for eons must be allowed to continue, while it also provides local oppor-tunity, farming system modification through the empirical process of trial and error, and the development of diverse sustainable livelihoods that protect local biodiversity and ecosystem services. But society must develop new priorities and policies to pro-mote and protect traditional agriculture so that it can continue to serve as a founda-tion for the conversion to sustainability.

When faced with limited options or alternatives, a culture can also show remark-able resilience and ingenuity in the conversion process. As described by Funes-Monzote in Chapter 10, Cuba chose to make dramatic changes in its agricultural sector after the dissolution of socialist Eastern Europe and the USSR. With local agrarian production viewed as the key to food security for the country, Cuba devel-oped a movement that has used input substitution focused at level 2 to transform a highly specialized, conventional, industrial, input-dependent food system into something far more sustainable. Due to the lack of access to external inputs and the


persistence of local knowledge of how to manage diverse agricultural systems, the conversion was able to take place quickly and broadly (Funes et al., 2002). But as Funes-Monzote points out, it has become clear that neither the conventional model nor the input substitution model will be versatile enough to ensure the sustainability of an increasingly diverse and heterogeneous agriculture. It is time to move from level 2 to levels 3 and 4. The emerging mixed-farming systems that he reviews in Chapter 10 are excellent examples of the conversion to these next levels.

Guzmán and Alonso (Chapter 11) analyze the conversion process at yet another scale—that of the entire European Union. Here, a more unified political and eco-nomic structure has been called upon to promote the conversion to what is referred to as ecological agriculture. The conversion process most often begins at the indi-vidual farm level, with farmers entering into level 2 conversion in order to meet the requirements of alternative markets developing for ecological products, but this occurs within the context of shared agrarian legislation and common tools for the development of ecological agriculture that are variably applied in each EU country. The on-farm part of the conversion most often deals with farmers learning how to substitute conventional inputs and practices with accepted alternatives (level 2), but it also includes social and economic issues that go beyond this second level. The norms for ecological agriculture have been developed as part of EU policy, with subsidies often applied as an incentive for their adoption. But because the EU economic policy is more oriented toward intercountry commerce, and very little toward intracountry markets, economic barriers such as access to markets and credit complicate the conversion process considerably. Farmers generally need institutional support to successfully move to the next levels in the conversion process. Apart from direct economic subsidies, support can include funding for research and training in ecological agriculture, encouraging more local consumption of sustainable products, investment in alternative food chains, and even the development of legal structures that benefit alternative production systems. Each region or country has its own local character and set of conditions that can promote the transition to more sustainable food system levels, and as a result, each one needs its own unique set of programs, incentives, and structures.

We see another regional example of the conversion process in Chapter 12 (Muramoto et al.). Japan has a long history of small-scale, diverse, multifunction family farms. But as modernization has had its impacts, farms have begun to lose their biodiversity and closed nutrient cycles, and they have become more dependent on energy-intensive inputs. Coupled with the movement of people out of agriculture, the aging of those who are still in it, and the loss of food self-sufficiency, these trends have pushed Japan into a food system crisis. In spite of these trends and pressures, and in some cases in response to them, there is still a strong organic sector in the Japanese food system. Since rice is such an integral part of the Japanese diet, and because the Japanese have a strong preference for the taste and texture of rice grown in their own country, local rice systems have received considerable research atten-tion, and this has helped them retain or reintegrate former sustainable practices and develop new, innovative ones. But it is the existing support for a culture of sustain-ability, most of it based in level 4 thinking, that forms the foundation of what could become a larger, more effective conversion movement in Japan.


In Chapter 13, Koocheki effectively integrates aspects of all levels of the conver-sion process as he describes the converconver-sion to sustainability occurring in the Middle East, especially in Iran, and how the process might be accelerated. Considered to be one of the original centers of the origin of agriculture, the Middle East continues to harbor a rich heritage and culture of dryland farming, nomadic pastoralism, and sus-tainable water harvest and delivery systems. At the same time, population growth is putting pressure on food production, modernization has threatened the sustainability of water resources, excess fertilization is causing water pollution, and government policy promotes large-scale, simplified, high-input alternatives. Despite these chal-lenges, progress is occurring as some farmers move through level 2 to level 3 in the conversion process. It will be level 4 thinking that will most likely move the process forward if, as Koocheki proposes, the region as a whole takes advantage of having a long tradition of small-scale, locally adapted, water-efficient, integrated agricultural practices from which it can draw for the conversion to sustainability.

Finally, Dumaresq and Ecker in Chapter 14 document how farmers in Australia have been working at level 3, especially when they design and implement more diverse cropping and grazing systems that integrate animals, crops, fallows, and pasture. The work of researchers—identifying indicators and monitoring the stages in the conversion process—is seen as an essential part of the conversion process. But for some of the more recent conversions, other issues and pressures are driving the conversion, such as nature conservation approaches, alternative food chains that bet-ter link farmers and consumers, and a growing environmental awareness and evolu-tion of ethics and values grounded in the concept of sustainability. Level 4 appears to be gathering strength.

The success of all the movements toward sustainability documented in these chapters will depend in large part on how well farmer knowledge is combined with new agroecological principles and then linked out with the end users of the food system, the folks who gather around the table and give thanks for the sustainable systems that have brought them their food.


Funes, F., García, L., Bourque, M., Pérez, N., and Rosset, P. 2002. Sustainable agriculture and resistance. Transforming food production in Cuba. Oakland, CA: Food First Books. Gliessman, S.R. 2001. Agroecosystem sustainability: Developing practical strategies. Boca

Raton, FL: CRC Press.

Gliessman, S.R. 2007. Agroecology: The ecology of sustainable food systems. Boca Raton, FL: CRC Press/Taylor & Francis Publishing Group.

Hill, S.B. 1985. Redesigning the food system for sustainability. Alternatives 12:32–36. Hill, S.B. 1998. Redesigning agroecosystems for environmental sustainability: A deep

sys-tems approach. Syssys-tems Research and Behavioral Science 15:391–402.

McMurtry, J. 2003. The Life Capital Calculus. Paper presented at the Canadian Association for Ecological Economics Conference (CANSEE), Jasper, Alberta, Canada, October 18. Rosset, P.M. 2006. Food is different: Why we must get the WTO out of agriculture. London:

Zed Books.




What Do We Know about

the Conversion Process?

Yields, Economics, Ecological

Processes, and Social Issues

Martha E. Rosemeyer


2.1 Introduction ... 16 2.2 Farmer Participation ... 18 2.3 Types of Conversion Research ... 18 2.3.1 Case Studies ... 18 2.3.2 Surveys ... 19 2.3.3 Farm Comparisons... 19 2.3.4 Systems Experiments ... 19 2.3.5 Single-Factor Experiments ...20 2.3.6 Study Design Considerations ...20 2.4 Parameters for Evaluating the Conversion Process ... 21 2.4.1 The Yield Parameter ... 21 Grains ...22 Vegetables and Small Fruits ...22 Perennials ...22 Animals ...23 2.4.2 Economic Analysis: Profitability ...23 Grains ...24 Vegetables and Small Fruits ...24 Perennials ...25 Summary ...25 2.4.3 Ecological Analysis ...25 Nutrient Dynamics ...26 Soil Nutrient Availability ...27 Microbial Biomass ...27 Soil Biodiversity ...28 Nematode Community Composition ... 29 Internal Nutrient Cycling ... 29 Agroecosystem Diversity ...30 Summary ...30


2.1 iNTroduCTioN

As farmers reduce their dependence on externally produced agrochemical inputs for food production and convert to more sustainable agroecosystems, evaluating and documenting the success of these conversion efforts is paramount. Assessing the results of conversion using a variety of research methodologies and looking at the triple bottom line of ecological, economic, and social factors allows a more precise and complete picture to emerge. It also permits the identification of obstacles in con-version to organic and sustainable agriculture.

The most difficult period for farmers converting from agrochemical-intensive systems is the transition period. In developed countries (where agrochemically inten-sive production systems are the norm) this period is characterized by a reduction in yields compared to what was obtained in the former conventional system. Over time, productivity is recovered, but the depth of the yield decrease and the amount of time needed to complete the conversion process are crucial because they can spell the difference between success and failure. These important variables depend greatly on the type of crop or crops being farmed, the local ecological situation, the prior history of management and input use, and the particular weather conditions during the period of transition.

In developing countries, in contrast, adoption of organic techniques can mean higher yields. This may also be true when the initial system uses locally prevalent methods under field conditions (low-intensive or conventional with few agrochemi-cal inputs). Badgley et al. (2007), in a survey of 293 publications of formal and infor-mal literature, found that conversion to organic agriculture in developing countries resulted in a 20 to 90% increase in yields, whereas conversion in developed countries resulted in a 3 to 20% decrease in yields. Another study surveyed 208 conversion projects in 52 developing countries and determined that of the 98 projects with the most reliable yield data, intensification of cultural techniques enabled an average per-project increase in food production of 93% (Pretty et al., 2003).

Farmers in developing countries who were using relatively chemically intensive methods prior to conversion experience yield decreases, similar to their counterparts 2.4.4 Pests ... 31 Weeds ... 31 Insects ... 33 Diseases ...34 Summary ...34 2.4.5 Energy ... 35 2.4.6 Social Factors Analysis ... 37 Labor ... 37 Satisfaction and Motivation ... 38 Health and Well-Being ... 39 2.5 Conclusions: Research and Extension Needs ...40 Acknowledgments ... 41 References ... 41


in developed countries. This suggests strongly that the effect on yield of the con-version depends on the intensity of the preconcon-version starting point (Parrott et al., 2006). In India, a study of seven farm pairs determined that the length of the transi-tion period was positively correlated with the amount of mineral fertilizers previ-ously used (de Jager and van der Werf, 1992). In Africa, conversion to organic fruit production for export was associated with increased yields in coffee, pineapples, and cacao, a result that the authors ascribe to the low amount of inputs used in conven-tional production (Gibbon and Bolwig, 2007).

The scope of the conversion—whether the farm is using input substitution to meet the current standards for certified organic production (level 2) or undergoing a full-scale system redesign (level 3)—is obviously a strong determinant of the length of the transition period. For some short-term annual crops, the time frame for a conversion to level 2 might be as short as three years, and for perennial crops and animal sys-tems the time period is probably at least five years or longer. Level 3 conversions can be even more lengthy, due to the large-scale biological and infrastructural changes that are involved. Data are scant on level 3 transitions, so most of this discussion will focus on level 2 conversions. These primarily involve conversions from conventional to organic systems, but also included are conversions to bioorganic, biodynamic, and more sustainable production systems (as defined by the respective studies).

One the most difficult aspects of conversion from conventional to organic may be the effort involved in rethinking one’s farm or agroecosystem, especially with the increased complexity of a level 3 system. The current agricultural focus on the production of only one or two cash crops may make the substitution of organic inputs for agrochemical (level 2) easier and more attractive than more complete redesign of the system. In the current conventional paradigm, the main crop is incorporated into a limited rotation. In a level 2 conversion there is often little change in the rotation sequence, and organically acceptable fertilizers and pesticides are substituted for con-ventional. Level 3 change, in contrast, demands the incorporation of diverse crops, the use of rotations, and the planting of perennials—which under certain circumstances of land ownership may be precluded. In addition to land tenure issues, transitioning to an organic system with rotation and perennials presents other challenges, such as new infrastructure needs and the need for diverse marketing strategies. The integration of livestock found on a diversified farm, though common in the past, challenges people without livestock experience. Additionally, sourcing organic stock and feed during certain periods may be a challenge to a more diverse level 3 system.

Why is the transition period important to study? For farmers converting from systems dependent on high agrochemical inputs, this is the critical period when the learning curve is steep and the farmer is not necessarily rewarded with profitability. If the transition period can be shortened or eliminated, or its challenges mitigated, this would allow more farmers to overcome a major barrier of conversion to organic or more sustainable production systems. In developing countries, understanding the yield increase that usually comes with conversion to organic practices can allow targeting of critical resources to small farmers in order to increase both food sov-ereignty and security for parts of the population experiencing the current food and economic crisis.


2.2 farmer ParTiCiPaTioN

A farmer’s involvement in developing the parameters of the study (defining the ques-tion or hypothesis, determining the type of research, etc.) is an important factor affecting both the applicability of the results of a study and its success in encourag-ing farmers to make changes in their agricultural systems (Selener, 1997). Exactly how and where the study is conducted (on an experiment station or on a farm) can affect the engagement of farmers. Even if the study is not conducted on a commer-cial farm, the representativeness of the land chosen will determine credibility of the study in the eyes of potential adopters (Petersen et al., 1999). An optimal research situation is a functioning commercial crop production unit whose owner-operator wishes to convert to a recognized alternative type of management, such as certified organic agriculture, and wants to participate in the redesign and management of the farm system during the conversion process (Swezey et al., 1994; Gliessman et al., 1996). Such a “farmer first” approach is considered essential in developing viable farming practices that have a realistic chance of adoption.

There are various levels of farmer participation in on-farm studies; they range from trials in which researchers make the management decisions to those in which farmers are the decision makers. Although this forms a continuum, Selener roughly breaks the possibilities down to four categories: (1) researcher-managed on-farm trials, (2) consultative researcher-managed on-farm trials, (3) collaborative farmer-researcher on-farm trials, and (4) farmer-managed participatory research. To estab-lish collaborative and farmer-managed studies, it is necessary to estabestab-lish open, respectful, equal communication between farmers and researchers (Selener, 1997). Historically, communication between farmers and scientists has been difficult, especially cross-culturally (Dusseldorp and Box, 1993). However, whatever form is taken, the more farmer collaboration there is, the greater the chances of acceptance by farmers (Selener, 1997; Rosemeyer, unpublished manuscript).

2.3 TyPes of CoNversioN researCh

There are many possible approaches to the study of the conversion process and the transition period: case studies, surveys, on-farm comparisons, systems experiments, and single-factor experiments. Examples of each approach and discussions of what data each can yield are discussed below. Observations on experimental design, includ-ing control treatments and the lengths of experiments, follow those discussions.

2.3.1 Case studies

A case study approach on an individual farm that describes the system and the eco-nomic and social factors of conversion in depth may be a compelling choice for farmers. For example, a study of the Krusenbaum dairy farm’s conversion to organic yielded important insights into critical social and economic factors (Posner et al., 1998). A case study of a converting vegetable farm in Cornwall, United Kingdom, has not only documented yields, weed control, pests and diseases, and soil fertility, but also examples of effective marketing and innovation (Sumption et al., 2004).


2.3.2 surveys

Surveys can provide important data on such issues as what motivates farmers to initiate conversion and what social and economic factors are crucial in successfully negotiating the transition process. As a good example, Jamison (2003) surveyed con-ventional and organic farmers to study the values that caused them to undergo the transition process. Surveys can also be used comparatively to study different types of systems, approaches, or strategies. For example, Lockeretz (1995) compared equal numbers of conventional and organic farms. Additionally, survey data from a repre-sentative sample of conventional and organic farms in transition can be essential in choosing an appropriate site for an experimental study of conversion processes.

2.3.3 Farm Comparisons

A common type of study compares transitioning farms with conventional counter-parts (Swezey et al., 1998; de Jager and van der Werf, 1992). Pairing transition-ing farms and conventional farms with respect to physical factors can provide some control by eliminating confounding factors such as differing soil types and other environmental factors. As an example of this type of study, in South India each of six transitioning farms was compared to a conventional equivalent with respect to agronomic and economic factors, including labor, and these farm pairs studied over a six-year rotation (de Jager and van der Werf, 1992).

2.3.4 systems experiments

Large-scale experiments comparing the performance of systems of production have been found to be of specific interest to farmers considering conversion. This type of experiment compares complex systems side by side in order to understand how they function as a whole (Drinkwater, 2002). The emphasis of study is usually on the interrelationships among the components of the agricultural system, such as those between plants and animals and between plants and elements of the physical envi-ronment, such as soil and water. Both the components and their relationships vary when comparing one system with another (e.g., a corn–soybean rotation versus graz-ing), making a cause-and-effect relationship more difficult to determine. However, comparing an entire system itself to another entire system is more realistic, and thus more credible to farmers, since the farmer is essentially choosing one system over another in considering what type of operation to adopt. Systems experiments can take place on either an experiment station or a farm, and farmers are usually at least consulted on the management, if not included as a part of the decision-making group. This type of experimentation may provide insights into ecologically signifi-cant parameters, as well as interactions between fertilization, pests and disease, and the environment (Bellows, 2002). The Rodale Farming Systems Trial (FST) study in Pennsylvania, initiated in 1981, was one of the first systems studies in the United States. It compares grain rotations with and without animal inputs, that is, with manures or green manure crops, respectively (Peters, 1991; Petersen et al., 1999). The Wisconsin Integrated Cropping Systems Trials (WICST), begun in 1989, is


another grains system study designed so that all rotations of each system are present in all years, facilitating comparison between systems (Posner et al., 1995).

The more similar the experiment is to real conditions, the greater the farmer confidence in the results. In systems experiments that involve transition to organic management, appropriately sized buffer strips between management treatments should be implemented; however, this has not always been the case (Lipson, 1997). Additionally, if all experimental treatments are present in all years, the effect of the year’s weather can be separated out as a variable (this is the case, for example, in the WICST) (Posner et al., 1995). It is possible to maintain the same rotational sequence, eliminating as a variable the difference in the initial crops undergoing conversion, if the study is given a “staggered” start. This means that for a four-year rotation, it will take four years for all the treatments to be present in all years. This increases the size of the experiment because there are more treatments; however, it is warranted since the type of crop that begins the conversion affects both yield and economic profitability. For example, in livestockless conversions in the United Kingdom, even after three years following the two-year transition period, the nature of the specific crop treatments planted during the transition period was reflected in different soil mineral nitrogen levels, yields, and gross margins (Rollett et al., 2007). This type of experiment provides useful information for the farmer on how to avoid the economic hardship of the transition period.

2.3.5 single-FaCtor experiments

Factorial experiments can complement systems experiments. Factorial design can be used to isolate specific components and identify cause-and-effect relationships (Drinkwater, 2002). Additionally, laboratory experiments can be critical for deter-mining the mechanism of an observed interaction in a systems experiment (Bellows, 2002). For example, at the two sites of the WICST plots, side experiments on weed control, rotational grazing, and cover crop selection, designed to isolate the specific factors responsible for observed system results, complemented the main systems experiments (Posner et al., 1995). More recently, experiments on certified organic land have been designed to help understand rotational effects on organic grain pro-duction (Hedtcke and Posner, 2005). Bulluck et al. (2002) compared alternative and synthetic fertilizer treatments in replicated field trials on three conventional and organic farms to see if beneficial microbes, including the fungus Trichoderma, were antagonistic to disease. On conventional farms, the use of alternative fertilizers, such as those used on organic farms, increased Trichoderma and decreased the plant pathogens Pythium and Phythopthora. These studies elucidate the mechanisms that explain the lower incidence of plant disease observed with alternative fertilizer use (Bulluck and Ristaino, 2002); as such, they contribute to an understanding of the transition process.

2.3.6 study design Considerations

In addition to comparing transitional farms with conventional control plots or farms, ecological studies may benefit from comparison with a nearby site supporting


relatively undisturbed habitat such as prairie or a forest (Leite et al., 2007) or a previous native or traditional agricultural system, such as a 1,000-year-old grass ley (Blakemore, 2000). Less overall energy (human, animal, or fossil fuel) is expended if the agroecosystem mimics the original ecosystem (Gliessman, 2000), and thus a native ecosystem may serve as an important baseline.

A number of authors have emphasized the extended amount of time needed to compare systems posttransition (Clark et al., 1998; Petersen et al., 1999; Reganold, 1988; Campos et al., 2000; de Jager and van der Werf, 1992), with the value of the experiment increasing over time. In a similar vein, a critique of methodologies for the comparison of organic and conventional farming systems emphasizes the impor-tance of long-term case studies (Lee and Fowler, 2002). The differences between the organic and conventional treatments postconversion highlight critical indicators that might be followed during transition.

The idea of farmer and researcher knowledge being complementary has been proposed by a number of researchers (Kloppenburg, 1991; Lyon, 1996; Bigelaar, 1997; Dusseldorp and Box, 1993). This complementarity is reflected in the types of experiments that are most compelling to each group. Case studies of farms undergoing transition provide a deeper understanding of the interactions of social, ecological, and economic factors, prioritizing the most important interactions and identifying important indicators that more hypothesis-driven experiments can sub-sequently explore. Surveys set the context for the question and frame its relevance. Systems experiments (especially those most useful to a farmer) and factorial studies that test single parameters (which are typically employed by researchers) support and validate each other, overcoming the specificity of a particular set of results at one or two locations and providing a more precise mechanism or explanation for the results in question.

2.4 ParameTers for evaluaTiNG The CoNversioN ProCess

In addition to monitoring the yield during the transition process as is most com-mon, it is important to consider a variety of other parameters. These can be divided into the categories of ecological, economic, and social; the specific factors to study depend on the nature of the question. Economic factors may include profitability and gross margin. Ecological factors may include soil microfauna, soil chemistry, popu-lations of pests, the incidence of diseases, nutrient cycling, and energy use. Social factors may include labor, health of farmers and farmworkers, general farm family well-being, and whether the next generation takes over the farm. Expectations for how these factors may change both during transition and as a result of conversion may play an important role in motivating a farmer or farming family to make the conversion (Padel, 2008; Padel and Foster, 2006; Jamison, 2003).

2.4.1 the yield parameter

Of critical importance to the farmer, the yield parameter is the result of many factors. Yields during conversion can either decrease or increase, depending on the chemical intensity of the initial system, as mentioned above. When yields decline as a result of




Related subjects :